RH - neoplasia - what gross and microscopic features are used in the diagnosis of tumours? Flashcards
How is the growth of rate used to determine whether a tumour is benign or malignant?
As a broad generalisation, a faster growth rate is associated with malignancy.
How is the nature of tissue invasion used to determine whether a tumour is benign or malignant?
Malignant tumours are invasive. So are fixed in position when palpated.
How is the nature of metastatic spread used to determine whether a tumour is benign or malignant?
If the tumour has spread via haematogenous, lymphatic or direct seeding within cavities. Then this is unequivocal evidence of malignancy.
How is differentiation of cells used to determine whether a tumour is benign or malignant?
Differentiation indicates the degree to which the tumours resemble the tissue of origin.
Well differentiated and a retained architecture is more likely to be a benign tumour.
An undifferentiated (anaplastic) and a loss of normal architecture indicates a malignant tumour.
What is pleomorphism?
Variation in the size and shape of cells and/or nuclei
What is anisocytosis?
Greater than normal variation in cell size.
What is anisokaryosis?
Greater than normal variation in nuclear size
What are the specific nuclear changes, due to malignancy?
Increased nuclear size Large nucleoli Multiple nucleoli Coarse chromatin Increased mitotic figures Abnormal mitotic figures
Why is anisocytosis and ansiokaryosis associated with malignancy?
Malignancy has an increased demand and metabolic activity.
What is the invasive behaviour of benign tumours?
Cohesive
Expansile
May be encapsulated
Not invasive
What is the invasive behaviour of malignant tumours?
Invasion
Infiltration and destruction of surrounding tissues.
What factors are used to differentiate between benign and malignant tumours?
Rate of growth Cellular differentiation Cytological features of malignancy Local tissue invasion Vascular invasion and metastasis
What are the properties of spindle-shaped cells?
Elongated, fusiform
Often arranged in streaming bundles
May have swirling or whirling patterns
What are the properties of epithelial cells?
Columnar, cuboidal polygonal, squamous or rounded shapes.
Adhesive junctions between cells (desmosomes).
May form cords, nests, lobules.
May form acing and tubular structures (glandular architecture)
What are the properties of round cells?
Discrete (individual) round or oval shapes.
May be arranged in sheets.
May be densely or loosely packed.
